Method of producing artificial silk



Patented Feb. 8, 1938 lemon or mnucmc. ARTIFICIAL wimmnnysen, Kenmore, u'ia John s. r a-ignmen 1 to E. I. dn-Pont de Nemours mingtoa, a corpora invention relates to threads, sheets, films,-

and other .materials produced by extruding (spinning or casting) cellulosic solutions, such as viscose, cellulose acetate and other, cellulosic i derivatives. More particularly, it relates to a method of producing materials of thc 'type men-' sbecmcauy. of producing rayon' having tioned having a diminished luster.-

it relates to: a method a diminished luster and preferably equal to or 10 lower than that possessed by natural silk.

Artificial thread produced by theusualviscose 1 process is characterized by a' high brilliant luster.

thread having duilingmat rial on previously formed thread.

According to ne specific procedure of thatprocess, a skein of artificial thread was alternately treated with a solution containing a soluble bar ium salt and a solution containing a sulphate g5 radical. frhe insoluble barium salt resulting from the reaction was produced on the surface of the thread and, though it reduced the luster, it did .-not give permanent effects. Frequently, in use the precipitated material was removed and as a In addition, the running 'qualities and the physical properties of the thread were seriously afiected. Moreover, the appearance and particu larly the luster did not simulate natural silk.

,5 Another proposed procedure for producingartificial thread having a mat appearance'consisted in incorporating into the viscose various materials, such as pigments, oils, fats and the like. The thread prgduced by this process consisted of a mass of cellulose having liquidor pig 'ment particles incorporated therein. Though this method produced a product of low luster,-the

type of luster was not comparable or similar to that of natural silk. Also, in view of the con- 45 stitution of the mass, there was a loss of tensile.

stren th.

Hollow artificial threads produced from'viscose possessed a. reduced luster. These hollow filaments because of their structure had a very low so tensile strength and thus were therefore not suitable for a great number of uses.

.Wehave found that we can produce an artificial thread by the viscose process, which is characterized by a luster equal toor lower than that 1- possessed by natural silk without sacrificing or sired. Several methods have already been {deimead SerialNo. m

*3 consequence an unattractive material resulted.

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reducing the tensile strength of the product. Specifically, we have found that by introducing into the viscose certain substances which disappear or are eliminated automatically at some stage in the usual production or finishing'of the thread, an artificial is produced which has a crinkled, channeled or porous exterior and is composed of a substantially solid cellulose mass free from foreign material. Due-to the structure of the exterior surface, it ra luster 'equalto 'or lower than that of artificial silk.

It is therefore an object of invention to provide a method of producing artificial thread by the viscose process having a luster lower than ordinary viscose silk and preferably equal to or lower than that of natural silk. Y

, Another object of this invention is to provide a method of prod icing'a mat appearingartificialthread consisting of solid cellulose free from foreign materialsand having a crinkled, porous or channeledsurface.

A further object of this invention is to provide a method of producing artificial thread which comprises the addition of a certain substance to viscose which automatically disappears in the usual process of producing or finishing the thread. s

Other objects will appear from the following description and appended claims. According to this invention, artificial thread having a mat appearance and a luster similar to .or lower than natural silk is produced by spinning in the usual manner a viscose solution containinga certain substance, which substance is distilled or.- otherwise removed at one or more stages in the process of producing the No special steps are necessary to .remove the added substance. The removal is automatically accomplished in the usual operations of finishing the thread. The product'of this process is substantially solid cellulose free from foreign or added materials. It is characterized by a crinkled, porous or channeled exterior surface and substantially its normal. tensile vstrength.

The substance added'to the viscose may be kerosene, turpentine or other comparatively high boiling volatile hydrocarbons or similar com- ;pounds or substances, solids or liquids which, due to lack of suitable terminology, is designated by 50 the term vaporizable substance. By the term vaporizable substance is meant a substance or compound which is insoluble in a spinning solution, or, if soluble in the spinning solution, in---"' soluble in the answering bath liquid, uwsi'ibutions.

: depends on the desired luster.

stance possessing a suficiently low vapor pressure so that it will not be removed from the spinning solution prior tospinning, particularly when the spinning solution is evacuated to remove the air, nor is it removed during spinning except in some instances a relatively small per cent may be removed, depending upon the substance chosen, said vapor pressure being sufficiently high so that thesubstance may be removed from the thread (as by steam distillation or otherwise) in washing, desulphuring, bleaching, drying or other steps in the usual spinning and finishing opera- It. is to be observed that this definition does not include such materials as ligroin, benzene, carbontetrachloride, carbon disulphide and similar materials of comparatively low boiling point and high vapor pressure which, though they result in the production of materials hBN'.

ing a reduced luster, do not resist evacuation of the spinning solution and/or are removed for the most part during spinning, so that no control of the resulting luster is possible. I

In accordance with this process, one or a plurality of the vaporizable compounds is introduced a into the viscose prior to the spinning thereof and is eliminated automatically in the process of producing the finished, thread without the aid of any special operations. It may be incorporated in the viscose at any time between dissolving the cellulose xanthate in caustic soda and the time the viscose is ready to be spun. It may aiso be added to the steeping caustic, to the alkali cellulom or to the carbon disulphide. Preferably, it is added to the mixture of caustic soda, water and .cellulose xanthate as these are being mixed. The substance may be added directly to the caustic solution ,or may be first mixed with asmall amount of caustic and then added to the main cherge.-- Preferably, an emulsion of the vaporizable compound in water is separately prepared in any suitable manner and this emulsion added to the batch. If desired, to aid the emulsification any of the commoniy known emulsifying agents for this purpose, including soaps, gums,

sulphonated vegetable oils, alkylated naphthalene and anthraquinone sulphonic acids (such as the Nekals) may be employed. a

The amount of vaporizable substance added Satisfactory results have been obtained by inccrporating approximately from 0.05% to 3.0% of the vaporizable compound in aviscose solution of the usual type, the proportions being based on weight. The

following specific examples indicate the preferred quantities of the various materials added:

Kerosene 0.5% emulsified with Monopole oil Turpentine" 0.6 emulsified with Nekal A. E. M.

produce-:1 in the usual manner, .there is'added a thick, creamy emulsion containing 14 cos. of a suitable emulsifying agent, such as M'onepole oil,

227 grams of kerosene and 280 cc. of water. The emulsion is preferably made, by dissolving the emulsifying agent in'the kerosene andthen adding the water witln'constant agitation. Upon the introduction of the emulsion in the viscose, the mass is agitated until the distribution of the emulsion is'coinplete. The viscose thus produced .is allowed to ripen and is spun and the thread produced processed in the usual manner. Duraioaeea ing the usual finishing operations, the kerosene is automatically substantially eliminated.

Any of the well-known coagulating baths may be used. We prefer, however, to use one containing zinc or analogous metals. A bath which has given satisfactory results consists of 11% sulphuric acid, 24% sodium sulphate and 0.8% zinc sulphate.

The product resulting from the method previously described consists of substantially pure cellulose. When examined under the microscope at a magnification not exceeding 440 diameters, it appears as a substantially solid thread showing no liquid, gas or solid particles. Magnification of 440 diameters is used as a standard because a regular viscose thread, if inspected at a sufli ciently great magnification, may show the presence of foreign liquid or solid particles or even 'of air which may not have been cempletely removed fromthe viscose.

v thread, except that the surface structure'and contour are crinkled, porous or channeled. This" feature permits greater scattering of light than is possible in the ordinary undelustered thread.

, Although this invention has been described specifically in connection with artificial thread produced from viscose, it is not limited thereto. The principles of this invention are equally applicable to other cellulose spinning solutions, as,

for instance, those containing cellulose derivatives such as celiulose acetate, cellulose ethers,

or the, like. Furthermore, the invention is not restricted to the production of artificial thread.

i substantially eliminated.

,It is likewise suitable in the manufacture of sheets I or films from cellulosic solutions of the type previously mentioned and including viscose, cellulose acetate, and cellulose ethers.

The term extruding used in the claims is intended to cover genericaily the extrusion of the cellulosic solution from the spinnerets in the production of threads or the casting of the solutions to produce sheets or films.

Since it is obvious that various changes may be made in the specific details of operation above set forth without departing from the nature or spirit of this invention, this invention is not re stricted thereto except as set forth in the appended claims. i

We claim:

having a luster equal to or lower than natural silk which comprises introducing a vaporizable high b-oiling'hydrocarbon in .a viscose solution, spinning said solution and finishing the thread in the usual manner wherebythe hydrocarbon is 2. A method of producing solid artificial thread 5o 1. A method ef-producing solid artificial thread having a luster equal to or lower than natural' silk which comprises introducing a vaporizable high boiling hydrocarbon in a viscose solution at some stage in the manufacture thereof, spinningsaid solutionand finishing the thread in the usual way whereby the hydrocarbon is substantially eliminated.

.3. A method of producing solid artificial thread.

having a luster equal to or iower than natural 1 silk which comprises introducing an emulsion of a vaporizable high boiling hydrocarbon in a viscose solution, spinning said solution andfinishing the thread in the usual manner whereby the hydrocarbon is substantially'eliminated.

4; A method of producing solid artificial thread having .a luster equal to .or less' -than natural silk which comprises introducing-0.05% to 3.0%. by

weight of a vaporizable high boiling hydrocarbon in a. viscose solution at some stage in the manufacture thereof, spinning said solution and finishing the thread in the usual manner, whereby the hydrocarbon is substantially eliminated.

5.. A method of producing solid artificial thread having a reduced luster which comprises incorporating kerosene in a viscose solution at some stage in the manufacture thereof, spinning said solution and finishing the thread in the usual manner whereby said kerosene is substantially eliminated.

6. A method of producing solid artificial thread having a reduced luster which comprises incorporating 0.05% to 3.0% by'weight of kerosene in a viscose solution at some stage in the manufacture thereof, spinning said solution and finishing the thread in the usual manner whereby said kerosene is substantially eliminated.

"7. A method of producing solid artificial thread having a reduced luster which comprises incorporating 0.5% by weight ,of kerosene in a viscose solution at some stage in the manufacture thereof, spinning said solution and finishing the thread in the usual manner. whereby said kerosene is substantially eliminated.

8. A method of producing solid artificial thread having a reduced luster which comprises incorporating an emulsion containing kerosene in a viscose solution in such quantities that from 0.05% to 3.0% by weight of kerosene is present, spinning said solution and finishing the thread in the usual manner, whe eby said kerosene is substantially eliminated.

9. A method of producing solid artificial thread having a reduced lusterwhich comprises incorporating a member of the terpene group in a viscose solution at some stage in the manufacture thereof, spinning said solution and finishing the J said solution and finishing the thread in the usual manner, whereby said turpentine is substantially eliminated.

'11. A method of producing solid artificial thread having a redu'cedluster which comprises incorporating 0.05% to 3.0%, by weight of turpentine in a viscose solution at some stage in the manufacture thereof, spinning said solution and finishing the thread in the usual manner, wherebysaid turpentine is substantially eliminated. N

-12. A method of producing solid artificial thread having a reduced-luster which comprises incorporating 0.6% by weight of turpentine in a viscose solution at some stage in -the manuiacture thereof, spinning said solution and finishing the thread in the usual manner, whereby-said turpentine is substantially eliminated.

13. A method of. producing solid artificial thread having a subdued luster which comprises incorporating'an emulsion containing turpentine in a viscose solution in suchquantities ,that from 0.05% .to 3.0% by weight of turpentine is present, spinning said solution and. finishing the thread in the usual manner, whereby said turpentineis substantial 14. A method of preparing solid. threads, films, sheets and the like which comprises extruding a cellulosic solution containing 0.05% to 3.0% by weight of kerosene in an aqueous bath and finishing the material in the usual manner whereby said kerosene is substantially eliminated.

15. A method of preparing solid threads, films. sheets and the like which comprises extruding a solution containing 0.05% to 3.0% by weight of turpentine and finishing the material in the usual manner whereby said turpentine is substantially eliminated.

16. A method of preparing solid threads, films, sheets and the like which comprises extruding a cellulosic solution containing a vaporizable high boiling hydrocarbon in an aqueous bath and finishing the material in the usual manner whereby said hydrocarbon is substantially eliminated.

17. A method of preparing solid threads, films, sheets and the like which comprises extruding a solution containing a member of a terpene group and finishing the material in the usual manner whereby the terpene is substantially eliminated.

18. A method of preparing solid threads, films, sheets and the like which comprises extruding a cellulosic solution containing 0.5% by weight of kerosene in an aqueous bath and finishing 'the material in the usual manner whereby said kerosene is substantially eliminated.

19. A method of preparing solid threads, films. sheets and the like which comprises extruding a solution containing 0.6% by weight of turpentine and finishing the material in the usual manner whereby said turpentine is substantially eliminated.

20. A method of preparing solidthreads, films, sheets and the like which comprises extruding a viscose solution containing 0.05% to' 3.0% by weight of kerosene and finishing the material in the usual manner whereby said kerosene is substantially eliminated.

21. A method of preparing solid threads, films, sheets and the like which comprises extruding a viscose solution containing 0.05% to 3.0% by weight of turpentine and finishing the material in the usual manner whereby said turpentine is substantially eliminated.

22. A method of preparing solid threads, films, sheets and the like which comprises extruding a viscose solution containing a vaporizable high inated.

24. A method of preparing solid threads, films, sheets and the like which comprises extruding a viscose solution containing 0.5% by weight of kerosene and finishing the material in the usual manner whereby said kerosene is substantially eliminated.

25. A method of preparing solid threads, films,

sheets and the like which comprises extruding a viscose solution containing 0.6% by weight of tub .pentine and finishing the material 'in the usual manner whereby said eliminated. z

somea'roms. 

